1. Field
The present invention relates to a continuously variable transmission for a hydraulic mechanism in hybrid cars with recovered power-split energy. A multi-function planet differential gear train pump is mainly adopted for further connecting to a friction brake, a hydraulic accumulator, a pressure sensor, a flow sensor, and a hydraulic valve controlling circuit so as to establish afore continuously variable transmission. Obviously, a hydraulic machinery composite transmission is provided along with a safe buffer and a buffer coupling as well as functions like recycling braking energy, storing hydraulic energy, recovering power, and operating in the continuously variable transmission. The present invention allows a car to reduce 20%˜40% driving power and to recycle more than 80% braking energy. If the traditional braking system malfunctions, the car could be still cushioned and braked by retrieving inertia kinetic energy. Thereby, the inertia kinetic energy is stored in the accumulator in a means of the potential energy of hydraulic static pressure. Preferably, the stored energy is provided for starting and accelerating the car. The present invention is especially suited to cars or buses that are often halted in the city.
2. Description of Related Art
The published continuously variable transmission with power-split energy is mainly composed by a hydraulic constant pump (motor), a hydraulic variable pump (motor), and a planet gear system. Such transmission is however bulky, the performance thereof is weak, and the structure of the same is adversely heavy. Moreover, noise is easily generated in afore transmission and this transmission merely provides a basic function. Even worse, the installation of the conventional transmission is difficult, so it is hard to be popular. For example, the hydraulic constant pump (motor), the hydraulic variable pump (motor), and the planet gear system provided by the Sundstrand Company in the U.S.A. further cooperate with two sets of friction clutches and four pairs of gear sets. Herein, the cooperation contributes to a continuously variable transmission for power-split hydraulic mechanism with parallel shafts DMT25. However, this transmission is also bulky and heavy, the function thereof is simple, and the installation thereof is still complicated. As a result, the company does not produce the same transmission anymore.